Truck scale



De. 22y 1953 H. HENDRICKSON TRUCK SCALE Filed Nov. 28, 1951 Patented Dec. 22, 1953 T so s 'rA'rEs PATEN T o F FICE 'TRUCK SCALE @Hugo Hendrickson, Port Angeles, Wash.

Application'November 28, 1951, ScrialNo. 258,567

(Cl. l26S-46) 1 Claim. 1

This Vinvention relates to weight indicating scales as .designed -for use on trucks,'trailers and Ys'irnilar `kinds of load hauling vehicles, to Y.indicate the approximate weight .of a 'load V.being 'supported thereby.

For .a better understanding ol? the .objects and uses ol" 'the present invention, fit will here be explained that .many States Ihave 'laws .or regulations .that limit .the weight of the lloafd that can be legally carried on highway vehicles .of Various kinds; .such .laws being .particularly applicable to trucks and trailersof the reighthauling types and generally concerns the .number .of pounds per square inch that can be applied through the vehicle wheels to the .road surface. ManyStates-havesetzthe load lirnit at 590 pounds yper square inch for trucksand trailers operating on concrete highways, rand scales have been installed at locations on the principal highways where weight of vehicles is checked to determine if there -is any violationof regulations.

Operators are generally desirous of hauling ina-Xirnum loads, and it frequently happens Vthey `inadvertently overload. This is primarily due tothe -fact .that yweighing facilities arenot readily available at the places of loading. In the logging industry, particularly, where it has becorne a general practise to transport large and heavy loads ci logs from forestto mill by means of truck andtrailer combinations, it Yis very dinicult for the vehicleoperator or the loader yto estimate `the weight of logs, and it is not the practise, nor -is it Apractical yto provide weighing facilities at the flogging areas.

In view of the above `explanatory matter, it has been the principal object of this invention to prov-ide a practical, relatively inexpensive and substantially accurate weight indicator or scale, lthat can dbe readily installed inthe common load :hauling vehicles of the truck and Vtrailer types, Yto indicate to a satisfactory `degree of accuracy, the weight of the Vload being carried thereon, thus to enable .the loperator to .ascertain the pounds per square inch being Vsustained by the roadway through the lvehicle wheels or tires, yand to avoid overloading.

'More specically stated, it is 'the object of the present invention to provide and to install a load 'weighing scale between l'a load support, which may be on, or apart o'f wheel truck, and a load-supporting vcross-bunk, whereby the weight of the .load applied through the support `and sustained Yby the truck Wheels will be indicated to the vehicle operator.

Itzis :a further object of .the present invention rto provide Aa scale .of the above stated character which is vin the form of `a .hollow compressible wafer .containing a hydraulic pressure medium, suitable for disposition between 4the support and bunk seas to sustain the weight of load thereon; the hydraulic chamber of ythe wafer being connected by a pipe line rto a pressure gauge `which ill operate underinuence of weight as applied `to lthe wafer and hydraulic medium therein, to designate the Weight of load 'being sustained.

Further objects .of the invention reside inithe fcietaiis .of construction of the scale; .in its application to `the vehicle, and to its mode .of operation, Aaswill hereinafter be fully described.

In accomplishing these other objects of the invention, VVIhave provided the improveddetails loi construction, the preferred forms `of which areillustratediin the accompanying drawings, wherein- Fig. l shows in elevation, a cross-bunk of a log-haulingtruck as supported upon a weighing device embodied by the present invention.

Fig. 2 is a cross-section taken on the line 2 2 in Fig. vLand diagrammatically showing the pipe line between the 'hydraulic wafer and pressure gauge.

i3 is a horizontal section, taken substantially on line E- in Fig. l.

lteferring more in detail to the drawings- Io Fig. l, H! designates what may be a load supw member as associated with a truck or trailer :chassis or with a wheel mounting truck or" a load hauling vehicle and l2 designates a cross-beam or bunk that is supported thereon for the sustaining of a load. It is generally the case, in a truck, trailer or rail car, that the rnber lli is located directly `over a set oi load cai ying Wheels so that the load, as sustained thereby, will be distributed equally to the Wheels regardless ofthe number used.

The cross-bunlr I2 is here shown to be supported directly above and upon the base member il 'through the mediacy of an interposed hydraulic water which comprises a principal part of the :resent weighing; means.

As best observed in Fig. l, the hydraulic wafer vvwhich is designated in its entirety by reference numeral .13, is located at a point midway of the ends of 'the parts EB and l2 and it comprises a circular bottom plate l5 of metal preferably a steel plate of suiiicient thickness to resist any flexing under the weight required to be sustained thereby. it is disposed upon and is ixedly secured in `horizontal position any suitable a s, 'to :the crossvsupport iii which, in Fig. 2, 'is shown to be a hollow beam. At its center, the il-ate ll5 is formed -with a circular hole 6 kin ich the lor-.fer end portion of a short tubular guide 'il is fixed; the tube being vertically disposed and. concentric of the disk. About its penphery, the disl: cr plate 'l5 has an upstanding rim .flange 13 .upon which a iia't disk or plate 20 is The :disk :or plate 26 is of the same ieter as plate l5 'and is supported on the rim fla :fe t8 in spaced relationship thereto, and it is w ded Vabout .its outer edge, as at 2l to the .disk l5 in :a leak proof and pressure tight joint.

.At its cen-ter the -dislz hole through which the tube il extends, and it is welded to Ii the tube and. to clisk i in a pressure tight joint as at '23. By this mode of assembly cf parts, a shallow chamber as at 2t in Fig. 2, is provied between the plates iii and 253. This chamber is hereinafter referred to as the pressure chamber.

The wafer i3 is disposed flatly and centered upon the cross support iii, as shown in Figs. 1 and 2, and is then welded as at 2t in Fig. 2, or otherwise xedly secured thereto. Resting upon the top plate '2t or" the wafer, is a circular capping plate ttl, provided at its center with a circular opening in which the lower end of a tubular guiele 32 is iixeo.. The tuoe 32 is rotatably and slidaoly fitted about the upper enol portion of the tube Between the top plate of the wafer and capping plate is a thin wear plate 34 that may he replaced when necessary. The cross-bunk i2 is disposed upon a diametrically across the capping and it is welded or otherwise secured thereto, as shown in Fig. 2. A pivot holt i ends clown through the bunk and central openings in the capping plate, wear plate and wafer, and then through the base member il and is secured oy a nut 33 at its lower end.

It is of importance to successful operation or the present device that the top plate of the wafer be of a Somewhat iiexiole nature, that is, it must be resilient to the extent that under a load sustained thereon, it can "ce downwardly deflected between its lines cf peripheral support at inner and outer fields 2i and Also, that the load. thereon e applied through the inediacy of the wear plate 'ii and that this niate be of an annular forni, concen'ric of the ing upon the support. The top plat terial so that the w 1 ly applied to the wear As an indication of ac l .e am mensicns or thicirness of plates, it will here mentioned, that in scale tiat has heen provided for use on a logging trailer truck, th iii-aferV has a cilaniet r of about 2G inches. The plate i5 is oi steel and /g inch thick. The top plate of the wafer is inch thick. The sustaining plate is about 'le inches in diameter and 7/2 inch thick. The spacing A-etwee plates iii anzi Eil, to provide the pressure charnher 2i for the vfireulic inecliuin is .t-2 inch eieep. The plate 2t is of a resilient material that will flex under load as reauireri to be sustained, but not beyond its elastic liinit.

To give visual indication of the weight or load carilcd or sustained by the wafer i3, I en.- ploy a pressure gauge of standard type, as tiesignaterl "ig. 2 35. This has a pressure connection fit with the pressure chamber t ci t' e wafer seen in Fig. 2. This ressure line may include terein a cut-out valve iii, and a tting it renovable plug et for lling the system a hydraulic medium. Preferably the gauge would be located in a place easily seen by the vehicle operator `iron-l the drivers seat.

To set the dei/icc for the pressure charnber 2o and pipe iine are nrst fill-eri with a nydraulic medium to the exclusion ci all air, which may be bled from the system through a hole in the top plate of the wafer. This hole is normally close by a plug best shown in Fig. 2, After the system has been filled with the hydraulic medium, the hand of the pressure gauge would be set at that indication which shows weight of the unloaded bunk. The gauge dial also would be graduated by placing loads of known weight on the bunk to establish the location of scale markings, and particularly to show the maximum load.

It will be understood that with the system thus installed, and the gauge dial properly graduated, the Vehicle operator can, for example, go into the forest and load the trucl: until the maximurn load has heen indicated on the dial. He can then proceed on the highway with safety.

Not only is the present scale useful as a means to-avoicl loading above the legal limit as established by highway or state regulations, but also is a means of preventing overloading the truck and. causing damage thereto.

There are various ways in which devices of this character may he made, and installed. However, the parts as shown are now believed to he the inost practical for the inode of application herein illustrated, but is not the intent that the manner ci mounting the wafer be in way restricted.

In the clairns which terminate this spcciiication, I will for salie of expediency, designate the cross-beam it as the base nierncer with the understanding this terni shall have reference not only to the beam iii as shown, but to any forni of base support through which weight of a load. carried on the bunk transmitted to the hase member through the niediacy of the wafer B, will be sustained and. distributed to the vehicle wheels which flirectly associated with the base member. terrn load carrying bea-in shall have reference to the hearn i5 or any similar load. susta' g mero er that can be mounted on the wafer. The term pressure gauge will have reference to the gauge as shown, or any similar form of loacl inelicator.

I claim:

In a load hauling vehicle of the truck or trailer type; a wheel truck. including a load. carr, g hase member and a load supporting cross-bunk arranged for support on the base member, and a loacl weight indicator comprising a hydraulic wafer interposed between the sai-fl salse niern ber anei cross-bunk, a pressure gauge and a pipe line connecting the pressure gauge and the chamber or the hydraulic wafer; sa-iel wafer coin.- prising a fiat, rigici, bottom plate, disposed ila upon the base member, a top plate of ilexihle metal joined with the bottom plate about its outer periphery and spaced therefrom to provide an intermediate chamber containing a hydraulic pressure medium, a wear plate :iisposefl on the top plate oi the wafer anfl a capping plate disposed on the wear plate and. supporting the cross-bunk. thereon, said base member, cross-bunk, wafer, wear plate and plate having aligned openings therethrough and a pivot bolt extending through said openings and joining the hase member and bunk.

HUGO HENDRI-CKSON.

References Citeri in the le or" this patent UNITED STATES PATENTS Number Name Date 2,365,589 Posten et al. Dec. 19, iii/ifi 2,592,501 Williams Apr. 8, FOREIGN PATENTS Number Country Date 195,793 Great Britain Apr. l2, 1922 398,687 Great Britain Sept. 2l, 1933 

